Refrigerating apparatus



March 11 11924o 1,486,551

C. G. SMITH REFRIGERATING APPARATUS Filed Jain. a, 1918 TURBWE 5g 32 25Patented Mar. 11, 1924.

CHARLES G. SMITH, OI CAMBRIDGE,

MASSACHUSETTS, ASSIGNOR, BY MESNE ASfiIGN- MmVTS, OF ONE-HALF TOLAURENCE K. MARSHALL, 0F SOMERVILLE, MASSA- REFRIGERATIN G APPARATUS.

Application filed January 8, 1918. Serial No. 210,841.

To all whom it may concern Be it known that 1, CHARLES G. SMITH, acitizen of the United States, residing at Cambridge, in the county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements in Refrigerating Apparatus; and I do hereby de-.clare the exact description of the invent1on,. such as following to bea full, clear, and

apparatus, which shall maintain the temperature of a room or box withinthe desired limits has long been recognized, but apparatus of this typewhich have been heretofore devised have required a considerable spacefor their installation, have been inefiicient,

and furthermore require more or less constant attention on the part ofthe operator. It is an object of the present invention to provide arefrigerating apparatus which -into the condenser, and

is compact in its construction, and which maintains the temperatureautomatically within desired limits, without any substantial attentionon the part of the operator.

lVith this object in view a feature of the invention contemplates theprovision of an evaporator partially filled with water and located inthe receptacle to be cooled, a condenser located outside of thereceptacle, and a pump interposedbetween the evaporator and condenserand adapted to maintain a vacuum over the surface of the water in theevaporator and discharge the water vapor produced by the presence of thevacuum connections between the condenser and the lower portion of theevaporator for returning the condensed water vapor to the evaporator.

A further feature of the present invention contemplates the provision ofa turbine directly connected to the water pump, a heater containingliquid mercury, connections between the'heater and turbine to cause themercury vapor under pressure to drive the turbine, and connectionsbetween the water vapor condenser into which the turbine exhausts andthe mercury heater to return the liquid mercury after condensation tothe heater.

With this construction a system is provided for handling the coolingliquid or water and the fluid which furnishes the motive or propellingpower to the pump.

self-contained Still'further features-of the invention consist incertain novel features of construction, combinations and arrangements ofparts hereinafter described and claimed, the advantages of which will beobvious to those skilled in the art from the following description.

In the accompanying drawings illustrating the preferred form of theinvention, Figure 1 represents a front elevation of a suitablereceptacle with the refrigerating apparatus embodied'therein; Fig. 2 isa detail illustrating the mechanism for controlling the pressure ofmercury vapor within the heater; and Fig. 3 is a detail illustrating thethermostat for controlling the fuel sup- The illustrated embodiment ofthe invention is applied to a refrigerator box 10 of the usual type,having a chamber 11 in the lower portion closed by doors 12 and adaptedto receive the food, amLa cooling chamber 14: in the upper portion whichordinarily receives the ice.

It is well understood by those skilled in the art that the evaporationof water absorbs heat from the surrounding atmosphere, and accordinglythe present invention utilizes this principle to abstract heat from theinterior of the refrigerator box and maintain the temperature at thedesired point. The evaporator comprises a metal container 15 which fitswithin the space 14, and is provided with a series of transversepartitions 16 connected with the walls of the container and adapted tofacilitate the transmission of heat from the walls to the interior ofthe container. As shown clearly in the drawing, this container ispartially filled with water, which is automatically maintained at asubstantially constant level as hereinafter described. Located above therefrigerator box is a closed condenser 17 which is connected with thecontainer through a pump 18 and communicating passage 19. The wallsof-oondenser 17 are cooled b air or any other well known cooling me iumcontacting with the exterior surface of the condenser. The pump 18 iscondenser is provided with a series of baffle plates 20 which areinclined downwardly toward that end of the condenser which is the moreremote from the pasage 21 leading to the pump. These baffle'plates serveto collect the condensed water vapor and direct the water into a.chamber 22 formed below the condenser, and having an inclined bottom 23which communicates with the upper end of a return pipe 24. This returnpipe 24 is connected with the bottom. of the evaporator through a pipe25, and causes the water within the evaporator to be consta-ntlyreplenished as the water vapor is withdrawn from the evaporator by thepump 18. In the normal operation of this apparatus then, water vapor isbeing continually withdrawn from the top of the container by the pump18, and liquid water is being continually supplied to the bottom of thecontainer through the passage 25, the level of the water in the pipe 24standing somewhat lower than the level of the water within theevaporator, as indicated at X, due to the difference in pressure onopposite sides of the pump 18.

In order to insulate the evaporator and the interior of the refrigeratorbox from the surrounding atmosphere and the condenser, the connection 19between the top of the evaporator and the suction side of the pum 18'consists of a tube 27 of material whic-i is a poor conductor of heat.

In order to operate the pump efficiently, a small turbine is connecteddirectly to the pump shaft, and is driven by mercury vapor generated ina heater which is directly connected to the turbine. The speed of thepump is conveniently varied by suitably varyifng the pressure of themercury vapor, and

as the thermal efficiency of mercury is exceptionally high, thisapparatus forms .an extremely compact and efficient means for operatingthe pump. Furthermore, the condenser for the water vapor is employed forcondensing the mercury vapor, and both the mercury and water whencondensed to liquid form are returned through the same pipe 24, the twoliquids automatically separating from each other on account of thedifference in specific gravity. As shown clearly in Fig. 1, the pump 18is supported upon a shaft 30 journaled at opposite ends in brackets 31and 32 and having a turbine 33 mounted thereon. This turbine ispreferably of the impulse type, and is connected with a main feed pipe35 which contains the mercury vapor under pressure. This feed pipepasses outside of the refrigerator box, and connnunicates with the upperportion of a heater 3? containing liquid mercury, as indicated at 38.The requisite heat for vaporizing the mercury under pressure is impartedby a burner indicated at and -located beneath the heater 37. The mercuryvapor is exhausted from the turbine 33 into the condenser 17 where it istransformed into liquid mercury and returned with the water into thepipe 24. This pipe, as shown clearly in Fig. 1, is connected with a pipe42 which connects directly with the bottom or lower portion of theheater 37, the two pipes forming in effect a vertical rise which extendsfrom the heater to the condenser. in the normal operation of theapparatus the mercury column in the pipe 42 stands at about the levelindicated at Y, or con siderably higher than the mercury within theheater 37, the difference in level being due to the difference inpressure within the pipes 35and 42. It will be noted that this mercurylevel, however, is below the water passage 25, and does not interferewith the continuous flow of water from the pipe 24 back to theevaporator 15.. The mercury column in the pipe 42 serves toautomatically feed the heater 37 without the interposition of any valveswhatsoever.

As the pressure of mercury vapor within the pipe 35 increases, themercury column within the 'pipe 42 rises, and in order to maintain asubstantially constant pressure of mercury vapor, mechanism is providedfor automatically regulating the burner 40 in accordance with the levelof the mercury cblumn in the pipe 42. To this end the fuel pipe 45 whichsupplies the burner is provided with a valve indicated at 46 andoperated by an arm 47 This arm is connected to a hollow vessel 48supported above and below by coils of light tubing 50 and 51,respectively, which are connected at opposite ends to the receptacle 48and to the riser 24. The normal level of the mercury is below theconnection between the coil 51 and the riser, and. when this mercurylevel rises the liquid mercury flows through the coil 51 and thence intothe vessel, displacing the water until the weight of the mercury issufficient to compress the coil of tubing 51 and operate the arm 47 toeither partially or wholly close the valve 46. When the supply of fuelto the burner is diminished, the pressure within the heater 37 graduallydrops, causing the mercury level to be lowered until the vessel-48 isagain free to be returned to its normal position, in which it isbalanced between the two coils of tubing 50 and 51. It will be obviousint) 'Figs. 1 and 3 of the drawings, a vessel 100 is pivoted at 104 inthe lower portion of the refrigerator and comprises a stem 103 and olppositely disposed bulbs 105 connected to e stem. The vessel is entirelysealed from the atmos here and contains a liquid, for example a cohol,which is supported in the lower bulb 105 by a flexible iaphragm 102.Theremaining portion of this bulb is filled with air which 1s expandedor contracted in accordance with the temperature surroundingthe bulb.The vessel is so designed that at a normal tem erature with-in therefrigerator, for examp le degrees, the liquid in the vessel uponopposite sides of the fulcrum 104 is balanced. The space in the upperbulb 105 above the liquid is filled with liquid vapor at a pressuresubstantially equal to the pressure of the air within the lower bulb 105at normal temperatures within the refri erator. If the temperaturewithin the re rigerator rises, how ever, the consequent flexing of thediaphragm 102 forces alcohol from the lower into the upper bulb 105 andoverbalances the vessel. A rocker valve 108 is located in the fuel pipe42 and is provided with an arm 112 connected at its lower endto a link111 which slides in the wall of the refrigerator. This link is connectedat its opposite end to one arm of a bell crank 109 fulcrumed within therefrigerator at 110 and having asecond arm connected to an operatingrod101 provided with a pair of stops 106 and 107 which are adapted to beengaged by the stem 103 of the containing vessel. With thisconstruction, when the vessel is rocked in either direction due to arise or fall in the temperature, the operating rod 101 is movedvertically to open or close the valve 108.

' It will be observed that by utilizing water as a cooling fluid, andmercury as a working fluid of greater density than the cooling fluid, itis possible to design a refrigerating system having a minimum of movingparts from which all valves are eliminated, and at I the same timeutilize to the weight of.

shown and described, it will be understood that this construction andarran ement is not essential except so far as speci ed in the claims,and may be changed or modified without departing from the broaderfeatures of the invention.

The invention having been described, what is claimed is:

1. A. refrigerating apparatus comprising an evaporator, a condenser, er,a vertical riser connecting the condenser with the evaporator andmercury heater, a pump located between the evaporator and condenser, amercury turbine connected to the. ump and adapted to discharge into thecon enser, and connections between the turbine and heater.

2. Control means for a refrigerating apparatus comprising a vaporturbine, a heater for generating actuating vapor for the turbine adaptedto contain mercury, a riser connected to the heater and adapted tomaintain a heater, a burner, a fuel supply pipe. for the burner, andconnections between the riser and fuel supply pipe for regulating thesupply of fuel to the burner in accordance with the mercury pressurewithin the heater.

3. Refrigerating apparatus including an evaporator tank and a pressuretank at a erating the valve proportionate to pressurev in the pressuretank, and thermostatic means adjacent the evaporating tank for actuatinganother of the valves proportionate to temperature variations.

4. Refrigerating apparatus including an evaporator for a cooling liquidof given density, a boiler for a liquid of greater density than saidcooling liquid, means for supplying heat to said boiler, a condenser,means whereby vapor from the denser liquid propels the vapor of thecooling liquid into said condenser, said last means dischargingthe-vapor of the denser liquid into said condenser, a discharge conduitfrom said condenser to said boiler, said conduit having an uprightportion in which the denser liquid collects at the bottom with thecooling liquid thereabove, and an outlet for the cooling liquid abovethe level of the denser liquid.

5. Refrigerating apparatus including an evaporator for a cooling liquidof given a mercury heatconstant supply of liquid mercury to the pressuretank to the tiirbine,

density, a boiler for a liquid of greater density than said coolingliquid, means for supplying heat to said boiler, a condenser, meanswhereby vapor from the denser li uid propels the vapor of the coolingliquid mto saidcondenser, said last means discharging the vapor of thedenser liquid into said condenser, a discharge conduit from saidcondenser to said boiler, said conduit having an upright portion inwhich the denser liquid collects at the bottom with the cooling 1i uidthereabovc, and an outlet in said con uit for the'cooling liquid, saidoutlet being in-' termediate said condenser and the level of the denserliquid in said conduit and discharging into said evaporator.

6. Refrigerating apparatus including an evaporator for water, a boilerfor mercury, means for supplyinghcatto said boiler, a condenser, meanswhereby mercury vapor from'said boiler propels water vapor from saidevaporator into said condenser, said last means discharging the mercuryvapor into. said condenser, a discharge conduit from said condenser tosaid boiler, said conduit having an upright portion connected at itslower end to the boiler below the level of the mercury theiein, wherebymercury collects at the bottom of said portion'with the waterthereabove, and an outlet for the water above the level of the mercury.

7. Refrigerating apparatus including an evaporator for a cooling liquidof given density, a boiler for a liquid of greater density than saidcooling liquid, means for supplying heat to said boiler, a condenser,means whereby vapor from the denser liquid propels the vapor of thecooling liquid into said condenser, said last means discharging thevapor of the denser liquid into said condenser, a discharge conduit fromsaid condenser to said boiler, said conduit having an upright portion inwhich the denser liquid collects at the bottom with the cooling liquidthereabove, an outlet for the cooling liquid above the level of thedenser liquid, and means connected with said conduit responsive tovariations of the level of the denser liquid therein with variations ofthe vapor pressure in said boiler to vary the heat supplied'to saidboiler.

8. Refrigerating ap aratus including an evaporator for a coo ing liquidof given -density, a boiler for a liquid of greater density than saidcooling liquid, means for supplying heat to said boiler, a condenser,means whereby vapor from the denser liquid propels the vapor of thecooling liquid mtp said condenser, said last means discharging the vaporof the denser liquid into said con- 00 denser, a discharge conduit fromsaid condenser to said boiler, said conduit having an upright portion inwhich the denser liquid collects at the bottom with the cooling liquidthereabove, an outlet for the cooling liquid above the level of thedenser. liquid, said conduit including a yieldingly supported reservoirin series between the condenser and .boiler, and means responsive tovariations in the level of said reservoir with variations in thepressure of said boiler to automatically vary the heat supplied to saidboiler.

9. Refrigerating apparatus including an evaporator for a cooling liquidof given density, a boiler for a liquid of greater density than saidcooling liquid, means for supplying heat to said boiler, a condenser,means whereby vapor from the denser liquid propels the vapor of thecooling liquid into said condenser, said last means discharging thevapor of the denser liquid into said condenser, a discharge conduit fromsaid condenser to said boiler, said conduit having an upright portion inwhich the denser liquid collects at the bottom with the cooling liquidthereabove, an outlet for the coolin liquid above the level oi thedenser liquid, said conduit including a reservoir in series between thecondenser and boiler, a pair of elastic coils in said conduit connectedrespectively to the upper and lower portions of said reservoir forsupporting said reservoir in vertically movable relation to said boiler,and means responsive to variations in the level of said reservoir withvariations in the pressure of said boiler to automatically vary the heatsupplied to said boiler.

CHARLES G. SMITH.

